Automatic mixing and discharging system for plural liquids



A ril 27,1926. v 1,582,279

I. W. KNIGHT AUTOMATIC MIXING AND DISCHARGING SYSTEM FOR PLURAL LIQUIDS Filed Nov, 5, 1924 f INVENTOR #34 W KN/f/T ATTORNEYS Patented Apr. 27, 1926.

UNITED STATES IRA W. KNIGHT, OF CRANSTON', RHODE ISLAND, ASSIGNOR TO GENERAL FIRE EX- TIN'GUISHER COMPANY, OF PROVIDENCE, RHODE ISLAND, A CORPORATION OF DELAWARE.

AUTOMATIC MIXING AND DISCI-IARGIITG SYSTEM FOR PLURAL LIQUIDS.

Application filed November 5, 1924.

To all whom it may comer-n:

Be it known that I, IRA W'. KNIGHT, a citizen of the United States, residing at Cranston, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Automatic Mixing and Discharging Systems for Plural Liquids, of which the following is a specification.

This invention relates to improvements in automatic mixing and discharging systems for plural liquids. More particularly it relates to fire extinguishing apparatus in which an acid solution, commonly known as, thefA solution, and an alkali solution, called the B solution, are maintained separate until discharge, whereupon they mix and react chemically to form an extinguishing agent, such as lire foam. In apparatus already proposed, the liquidsare stored in separate containers from each of which a siphon leads to a common outlet. In order that these siphons may start working upon the opening of said outlet, it is necessary that they be duly filled with some liquid. The liquid of the container may rise in the intake leg, but it remains to fill the discharge leg of each, i. e., to prime it, preferably with some neutral liquid. This isaccomplished by opening the crest of each siphon, pouring in the neutral liquid up to the desired level, and then closing the crest securely so that each is sealed airtight. If the level of priming is not high enough in the discharge legs, or if either vent is left open by oversight, of leaks, the siphonic action cannot occur. And unfortunately such a condition will not be apparent until the need of action arises.

The present invention provides a specific- These objects are attained by having one" Serial No. 747,980.

' siphon, preferably that in the B? or nondescends through the B solution, and

hence this connection can conveniently be made. At the crest of this latter siphon is the single vent, for the two siphons, and this is closed by a plug which in the illus-' trated embodiment of the invention is affixed to and forms a part of the cover that tops the containers. removed, theliquid's are poured into their respective containers until the desired level is reached. The acid or A solution simply riscsin the entrance leg of its siphon, pushing the air out. through the vent, until it stands atthe same height in that leg and in the tank. hen the B solution is poured With this cover and plug.

in, this liquid similarly rises in the entrance i leg of its siphon ,until its crest is reached,

whereupon it flows over this crest into the dis-V charge legs of both siphons, they being pref erably connected at their lower extremities warning, byits improper positiomthat complete replacement of the plug has not been effected. Thusthe invention eliminates the danger of the siphon legs be ng notsuliiciently primed by making the legs self primin and 'reatlv lessens thee uallv disastrous danger'of failure to replace the vent plug, by making such failure evident to one glancing even casually at the supposedly charged apparatus.

It'is intended that the patent shall cover, by suitable expression in the amended claims,

exist in the invention disclosed.

ln the accompanylng drawings the smgle figure IS an elevation showmg, insection, a

whatever features of patentable novelty tank containing the two liquids in separate compartments, with cover and vent plug associated therewith, and in view uncut, the siphons, their connections, and the common discharge.

Referring to the drawings, the tank is divided into two compartments 8 and 10, by a partition 14, to form. separate containers .t'or thetwo liquids; the acid solution being in the compartment 10 having a lead or other non-corrosive lining 16. From this latter container rises the entrance leg 18, also noncorrosive, of the siphon 18. As illustrated this curves over the partition 14:, and to have a minimum of piping exposed to corrosion, descends through the alkali solution to the connection 20 with the common pipe 21. This latter has one or more single outlets controlled preferably by some thermo-responsive means, as an automatic sprinkler head Only one such outlet is illustrated, and this is closed by the containers, as would be suitable where the containers are to be placed close over the vat or other thing which is to be protected, for this is the position for quickest and best action.

The other siphon, 12 for the B solution, has the bottom of its entrance leg 12 at the same level as the entrance leg 18 of the A solution siphon, but its crest is arranged below the level at which the charge of B solution is desired to stand when ready for action. Its discharge leg 12 likewise descends through the alkali solution to the connecting pipe 20, and common discharge 21. It connected to the discharge leg 18 of the longer siphon by a pipe 2 1 near the crest of siphon 12. This cross connection need not be actually at the crest of the shorter siphon, apparatus embodying theinvention has operated satisfactorily ith this con-- nection as low as one-third the way down from the top of the B solution siphon. It is desirable that. it be located near the crest, however, as this prevents the leaving of any appreciable air space in the shorter siphon, and allows the liquid to rise and to stand high enough in its discharge leg to in sure successful siphonie discharge when the outlet through sprinkler 22 is opened. In certain cases, as where the oulet of the siphon is a considerable distance below the liquid level, this connection may be below the tank and still be high enough to be effective. In fact it may be. omitted it the discharge leg above the outlet is long enough to create suiiicient suction to pull the liquids over the crests of lZhQlIHYGSlWCiLlVC siphons when the common outlet is opened.

At the top of the siphon 18, is a vent 26 through which the air from both siphons escapes as the liquids are poured into their coirtainers, andrise in the-two siphons, but which must be tightly closed when the charging is completed.

The closure for this vent is a plug 28. This is fastened to the cover 30, whose peripheral flange 30 lits nicely around the top edge of the tank. This flange is less deep than the linear distance traveled by the plug in being screwed into the vent, so that it through carelessness the plug is left merely placed on the edge of the vent, the flange wil not be below the top of the tank, thereby disclosing to an observer that neither it or the plug have been properly replaced. By making a mark on the tank wall to indicate where the lower edge of the flange should be when the plug is tight, observation of the tank will readily show whether the plug is fully in, or is in position where air leakage may occur suilicient to prevent action of the siphon. As a further means to warn an ob:-'=crvcr that the plug has not been replaced, the end of the plug may be misshapen as at 28 so that ii: merely inserted in the vent hole it can not scat evenly but will tilt, causing the cover to assume an awry position, easily noticed by anyone glancing at the tank.

In operation, when the sprinkler head, or other discharge valve is opened, the liquid in the two discharge legs 12 and 18 de scends simultaneously into the pipe 20 and thence through the outlet. This first dis charge is only 13 solution, but as this liquid sinks in both discharge legs it pulls over the liquids in the: entrance legs in ac cordance with the siphonic principle, so that almost immediately following the opening of the outlet both solutions will be discharging together. And this sin'mliancous discharge will continue until the level in each containor reaches the lower end of its respective entrance leg. The difference in length of pipe travelled by the liquids is so small that the excess of frictional resistance in the longer siphon is negligible. Accordingly, since the ellective heads of the liquids are equal. they are emptied together in the same time. The liquids can be made of proper relative strength, as by using the acid in a suitable degree or dilution, to make the uniform dis charge rate suitable for the chemical reaction. Gr, it a discharge in some other ratio is desired the size of pipes and size and arrangement of containers can be varied accordingly. The connection 21 is so small in cross section that the opportunity for transfer oi one liquid into the discharge leg oi the other is of no consequence. In fact, the flow of the liquids downward past the small openings of the connecting pipe 2i, probably acts with sulficient suction to establish a partial vacuum in the connection itself,

and thus to prevent any mixing of the'liquids from the siphon may lead to a greater dis-.

tance from the containers and may have llil more than one outlet at each of which there is opportunity, as at 20, for the two liquids to flow into a single pipe 21 and to a discharge controlling device, as at 22, which may bethe occasion for setting the apparatus into action. In any such case the length of pipe 21 leading from the place where the discharging liquids come together has been found to work best when it'is not long enough for any considerable reaction to oc cur with generation of gaswithinit For example, where the pipe 21 is a full size extension of outlet piping having 1% inches diameter, it is found that its outlet should be reached in not exceeding 15 to 18 inches after the liquids have'come together. Ob viously this length may vary with circumstances, among which are thehead, the size of pipes, and the vigor of chemical action occurring after the liquids come together.

I claim:

1. An automatic mixing and discharging system for plural liquids comprising the, combination, with separate containers for said liquids, of a siphon for one of the containers rising above the normal level of its liquid, having a crest vent and a closure therefor; a siphon for the second container having its crest below the normal level of its liquid; means connecting the discharge legs of said siphons, whereby the two discharge legs are primed by the filling of the second container to normal level; and a common valved outlet whose opening effects simultaneous discharge of both siphons.

2. An automatic mixing and discharging system for plural liquids comprising the combination, with separate containers for said liquids, of a siphon for one of the containers rising above the normal level of its liquid, having a crest vent and a closure therefor; and a siphon for the second container having its crest below the normal level of its liquid; the discharge legs of the said siphons having a common outletwith control valve normally closed at their lower ends and having communication with each other near the crest of the submerged siphon whereby the discharge legs of both siphons are primed by the filling of the second container to normal level; the opening of said valve effecting simultaneous discharge of both liquids.

3, An automatic mixing and discharging system for plural liquids comprising the combination, with separate containers for said liquids, one of which has a removable cover, of siphons for the liquids having connections between their discharge legs, a valved outlet common to both siphons and one of them adapted to have its discharge leg filled from its container through its intake leg, whereby upon filling the containers the said siphons are primed; a crest vent in the other siphon; and a removable plug closure forsaid vent-associated with said cover so that the position of the closure plug in respect to being seated and closing the vent is indicated by the position of said cover with respect to the container.

4-. An automatic mixing and discharging system for plural liquids comprising the combination with their separate containers,

of siphons of differential crestheight, one being above and the other below the level of its liquid when its container is normally filled, whereby upon the filling of the container whose siphon has the higher crest, its

dischargeleg is unaffected; a union between IRA WV. KNIGHT. 

